After the patients have been adequately treated with antibiotics, source control and circulatory and respiratory stabilized, the patient will be moved to the Magnetic resonance imaging (MRI)-suite and placed in the MRI-camera. We plan to, at the same time, study renal blood flow (RBF) and oxygenation with 3 different MRI techniques; arterial spin labeling (ASL), Blood oxygen level dependent (BOLD)-technique, and diffusion at four conditions;